Optogenetic tools for activating and silencing specific neurons embedded within dense brain networks, in a temporally precise fashion using light, are key to understanding the roles that specific neurons play in behavior, neural computation, and disease. In our Phase I SBIR, Ferro Solutions and the Boyden lab at MIT collaborated to develop a fully wirelessly powered and wirelessly controlled headborne device, small enough to be carried on a mouse head, and containing an array of multiple blue LEDs for direct stimulation of surface structures. In our Phase II SBIR, we propose to extend this device with a number of new capabilities, thus creating a powerful and easy-to-use toolbox to support a large range of optogenetics experiments, both for empowering basic science researchers, and as prototypes of future clinical devices. Specifically, we propose to add new light sources, add wireless targeting of deep structures, and improve the power and range of the system. The system will be of utility to scientists working with mice and rats to study neural circuits, and to clinicians as prototypes of optical neural control prosthetics. We will work to make our devices available and easy to use by scientists and clinicians in academia and industry.